by groundspeed do you mean how fast the robot is moving? because the ground doesnt really move that much otherwise and for airspeed you could use a pinwheel hooked upto a tiny generator and measure the power outputs. but thats just my majorly ghetto way of doing it

Just a quick question on accelerometers: My testbed is going to replicate different conditions on my final robot which will have a vertical movement of several cm (5-10cm guesstimation at this point) with a frequency of 0.8 - 3Hz (varies with speed).Will this affect the readings I receive in all axis or just the vertical?Being a variable low frequency, will it be easy enough to filter out?

accelerometers are great in theory, though they can be quite tricky in practice. holding them straight, 1 of the axes (usually y) will always register an acceleration due to gravity(the accelerometer isnt moving but gravity is causing stress on the microstructures causing an acceleration reading on an axis). if the accelerometer is tilted then more than 1 axis will be affected by gravity. The difficuly comes from trying to differentiate which part of the reading is coming from movement and which part is coming from gravity. If your movement make a slight tilting motion as well as a forward/backward motion then it will affect the other axes but only because the gravity reading is switching axes. Getting to grips with differentiating gravity from actual readings is essential for using accelerometers.

1mph will do just fine.Because this is only for learning at the moment, the cheapest reliable solution will be the best. As long as I don't end up with a sensor I can't interpret data from I think I'll manage. (Please note I did say think )